The present invention relates to a diagnostic apparatus, and more particularly, to an apparatus for preparing a liquid suspension of particles, such as an aqueous suspension of parasite eggs, for microscopic examination.
It is routine in medical and veterinary practice, where endoparasites are suspected, to analyze the host's fecal material for the presence of endoparasite eggs. In one common fecal analysis test, the fecal material is placed in a vial, suspended in a quantity of a flotation medium, and filtered to remove larger-than-desired particles. The vial is then completely filled with medium until a convex crown is formed at the vial's upper opening. Particles in the suspension are transferred to an examination slide by touching the slide to the crown.
The just-described fecal analysis procedure is somewhat inefficient in that flotation liquid must be added to the vial twice, once to suspend the fecal sample, and again to raise the level of the suspension to form a crown. Further, if the vial is overfilled, or not carefully handled when filled, the suspension may overflow the vial and contaminate the area where the test is being conducted. Also, after completion of the test, it may be difficult to dispose of the filled vial without additional contamination problems.
One general object of the present invention is to provide an apparatus in fecal analysis which substantially overcomes problems noted above associated with prior art fecal analysis techniques.
Another object of the invention is to provide an apparatus more generally usable to prepare a suspension of particles for assay by examination.
Still another object of the invention is to provide such apparatus which is constructed to minimize the possibility of sample contamination both during and after a test is performed.
Still another object of the invention is to provide apparatus which may be used in combination with commercially available, conventional disposable vials in perfoming suspensionparticle analysis.
The apparatus of the present invention includes a vial for holding a liquid suspension of particles, such as an aqueous suspension of parasite eggs. A tubular cup-like plunger, which is insertable in the vial, receives, through a perforated base, suspension which is displaced upwardly as the plunger is lowered into the vial. Such base acts as a filter for selectively passing suspension particles according to particle size.
The apparatus is intended to be used by placing at least a predetermined amount of suspension in the vial and inserting the plunger into the vial until a convex crown is formed at the plunger's upper open end. The suspension is collected by touching a slide to the crown.
After suspension particles have been transferred to the examination slide, the plunger is pushed fully into the vial, causing liquid in the tube to spill into an annular space between the vial and the plunger. The vial is then capped to seal completely the contents therein, and discarded.